CN105622363B - Technology for preparing vanillyl alcohol ether by one-step method - Google Patents

Abstract

The invention relates to a process for preparing vanillyl alcohol ether by a one-step method. The process jointly utilizes the co-catalysis of a nano ruthenium metal catalyst and an immobilized tin phosphotungstate catalyst, and vanillin reacts in a reaction kettle under the hydrogen pressure of 1-2 MPa and an alcohol solvent at the temperature of 20-60 ℃ for 18-24 h to obtain vanillyl alcohol ether. The process can be carried out under mild conditions, is green and environment-friendly, has high product yield, and is suitable for industrial production.

Description

Process for preparing vanillyl alcohol ether by one-step method

technical field

The invention relates to a production process of vanillyl alcohol ether, in particular to a one-step preparation method using vanillin as a raw material, n-butanol as a solvent, hydrogen as a reducing agent, and catalyzed by a nanometer ruthenium metal catalyst and an immobilized tin phosphotungstate catalyst Process of vanillyl ether.

Background technique

Vanillyl ether, also known as capsicum ether, has a strong curry aroma and is widely used as a food flavoring agent. And because of the remarkable heating effect, it has the effect of accelerating the blood circulation of the human body and causing a local heating sensation. As a heating agent in cosmetics, it is especially suitable for women's cleansing in cold winter, and as a heating agent in plasters, it has the effect of dispelling wind and cold. Among them, vanillyl butyl ether is most widely used in food and cosmetics. In the traditional synthesis method, it is obtained by reacting sodium aroxyl and chlorobutane. However, this method needs to remove sodium chloride, and the separation is complicated. The dehydration of vanillyl alcohol and n-butanol in an acid catalyst to obtain vanillyl butyl ether is a reasonable choice, and only one water needs to be released as a by-product. However, the acid-catalyzed dehydration system generally has a low yield and needs to be added to a water outlet device, and it is easy to produce vanillyl alcohol ether and butyl ether as by-products. Secondly, vanillyl alcohol is more expensive as a raw material, which increases the production cost. It is a good method to use vanillin as a raw material to reduce vanillyl alcohol through sodium borohydride, and then to synthesize vanillyl butyl ether with n-butanol. However, this method is carried out in two steps, which increases the complexity of the process. Using sodium borohydride as a reducing agent is not only expensive, but also cannot be reused. Therefore, the development of a process for obtaining vanillyl ether from vanillin in one step is of great industrial application value.

Contents of the invention

The object of the present invention is to provide a kind of one-step process for preparing vanillyl alcohol ether technology in order to improve the deficiencies of the prior art, using vanillin as raw material, corresponding fatty alcohol as solvent, hydrogen as reducing agent, through nanometer ruthenium metal catalyst The vanillyl ether can be obtained in one step by catalyzing with the immobilized tin phosphotungstic acid catalyst.

The technical scheme of the present invention is: a process for preparing vanillyl alcohol ether in one step, which is characterized in that: the raw material vanillin is dissolved in an alcohol solvent and placed in a reaction kettle, and a nanometer ruthenium metal catalyst and a tin phosphotungstate catalyst are added And fill in 1-2MPa hydrogen, control the reaction temperature at 20-60°C, and the reaction time is 18-24h, and obtain the vanillyl alcohol ether in one step through catalyst catalysis.

Preferably, the above-mentioned alcohol solvent is monohydric alcohol such as methanol, ethanol, n-butanol or isopropanol; preferably, the concentration of the raw material vanillin in the solvent is 0.5-1.5 mol/L.

Preferably, the above-mentioned nanometer ruthenium metal catalyst is a product of ruthenium trichloride loaded on an oxide and reduced by hydrogen, wherein the mass ratio of ruthenium trichloride to the oxide is 1: (20-40); Aluminum, titanium dioxide, silicon dioxide or ferroferric oxide, etc. Adopt conventional method to prepare and get final product, for example: ruthenium trichloride is dissolved in ethanol, add oxide compound as carrier, stir, evaporate to dryness ethanol and obtain precatalyst material, wherein the mass ratio of ruthenium trichloride and oxide compound is 1:( 20-40), the pre-catalyzed material is placed in a hydrogen atmosphere, and reduced at 180-220° C. for 2-4 hours.

Preferably, the solid-supported tin phosphotungstic acid catalyst is a solid acid catalyst obtained by carbonizing tin phosphotungstic acid supported on activated carbon and covered with furfural on the surface; wherein the mass ratio of tin phosphotungstic acid to activated carbon is 1:(1.25～2 ), the mass ratio of furfural to tin phosphotungstate is 1:(2～3). Its preparation method is the method provided in the reference patent (Application No. 201410168401.8 A solid acid catalyst and its preparation method and application).

Preferably, the amount of the above-mentioned nanometer ruthenium metal catalyst is 20-40% of the mass of the raw material vanillin; the amount of the immobilized tin phosphotungstate catalyst is 5-25% of the mass of the vanillin.

Beneficial effect:

The process route of the invention is simple, the catalyst can be reused many times, the reaction condition is mild, the method is green and environment-friendly, the separation of vanillyl alcohol ether is simple, and there is no waste discharge.

detailed description

Example 1:

Preparation of nano-ruthenium metal catalyst A: Dissolve 10 g of ruthenium trichloride in ethanol, add 200 g of silicon dioxide, stir for 24 hours, evaporate the ethanol to dryness to obtain a solid, and reduce the solid under hydrogen at 180° C. for 3 hours to obtain catalyst A.

Example 2:

Preparation of nano-ruthenium metal catalyst B: Dissolve 10 g of ruthenium trichloride in ethanol, add 400 g of aluminum oxide, stir for 24 hours, evaporate the ethanol to dryness to obtain a solid, and reduce the solid under hydrogen at 220°C for 2 hours to obtain catalyst B.

Example 3:

Preparation of nano-ruthenium metal catalyst C: Dissolve 10 g of ruthenium trichloride in ethanol, add 300 g of titanium dioxide, stir for 24 hours, evaporate the ethanol to dryness to obtain a solid, and reduce the solid under hydrogen at 200° C. for 4 hours to obtain catalyst C.

Example 4:

Preparation of nano-ruthenium metal catalyst D: Dissolve 10 g of ruthenium trichloride in ethanol, add 250 g of ferric oxide, stir for 24 hours, evaporate the ethanol to dryness to obtain a solid, and reduce the solid under hydrogen at 210°C for 3 hours to obtain catalyst D.

Example 5:

Preparation of solid-supported tin phosphotungstic acid catalyst E: Dissolve 300g tin phosphotungstic acid in water, add 600g activated carbon to the tin phosphotungstic acid solution, stir for 6h, add 100g furfural and stir for 4h, evaporate to dryness in vacuo to obtain a black solid, the Catalyst E was obtained by carbonizing the black solid at 450 °C for 4 h under argon.

Embodiment 6:

Preparation of solid-supported tin phosphotungstic acid catalyst F: Dissolve 400g tin phosphotungstic acid in water, add 500g activated carbon to the tin phosphotungstic acid solution, stir for 6h, add 200g furfural and stir for 4h, evaporate to dryness in vacuo to obtain a black solid, the Catalyst F was obtained by carbonizing the black solid at 350 °C for 4 h under argon.

Embodiment 7:

Preparation of solid-supported tin phosphotungstate catalyst G: Dissolve 350g tin phosphotungstate in water, add 550g activated carbon to the tin phosphotungstate solution, stir for 6 hours, add 150g furfural and stir for 4 hours, evaporate to dryness in vacuo to obtain a black solid, the Catalyst G was obtained by carbonizing the black solid at 500 °C for 2 h under argon.

Embodiment 8:

Add 1 kg of vanillin, 13.1 liters of n-butanol (the concentration of vanillin is 0.5 mol/L), 0.2 kg of catalyst A and 0.05 kg of catalyst E in the reactor, and fill with 1 MPa hydrogen, heat to 20 ° C for 18 hours, Detect that the reaction of vanillin is complete, stop heating, filter the catalyst after the reaction kettle is cooled, and dry the catalyst directly before use. The excess butanol was removed from the filtrate by rotary evaporation to obtain 1.33 kg of vanillyl butyl ether, with a yield of 96% and a purity of >98%.

Embodiment 9:

Add 1 kg of vanillin, 6.6 liters of ethanol (concentration of vanillin is 1 mol/L), 0.3 kg of catalyst B and 0.15 kg of catalyst F into the reaction kettle, fill with 1.5 MPa hydrogen, heat to 30°C for 24 hours, and detect vanilla After the aldehyde reaction is complete, stop heating, filter the catalyst after the reactor is cooled, and dry the catalyst directly before using it. Excess ethanol was removed from the filtrate by rotary evaporation to obtain 1.36 kg of vanillyl ethyl ether with a yield of 98% and a purity of >98%.

Example 10:

Add 1 kg of vanillin, 4.4 liters of isopropanol (concentration of vanillin is 1.5 mol/L), 0.4 kg of catalyst C and 0.25 kg of catalyst G into the reaction kettle, fill with 1.8MPa hydrogen, heat to 40°C for 22 hours , detect that the vanillin reaction is complete, stop heating, filter the catalyst after the reaction kettle is cooled, and dry the catalyst directly before use. The excess isopropanol was removed by rotary evaporation from the filtrate to obtain 1.36 kg of vanillyl isopropyl ether with a yield of 98% and a purity of >98%.

Example 11:

Add 1 kg of ethyl vanillin, 4 liters of methanol (the concentration of ethyl vanillin is 1.5 mol/L), 0.4 kg of catalyst D and 0.05 kg of catalyst G in the reactor, and fill with 2MPa hydrogen, heat to 60°C for reaction After 19 hours, it was detected that the reaction of ethyl vanillin was complete, the heating was stopped, the catalyst was filtered after the reactor was cooled, and the catalyst was directly dried before use. The excess methanol was removed from the filtrate by rotary evaporation to obtain 1.34 kg of ethyl vanillyl methyl ether with a yield of 97% and a purity of >98%.

Example 12:

Add 1 kg of ethyl vanillin, 6 liters of isopropanol (the concentration of ethyl vanillin is 1 mol/L), 0.3 kg of catalyst B and 0.15 kg of catalyst F in the reaction kettle, fill with 1 MPa hydrogen, and heat to 40°C After 23 hours of reaction, it was detected that the reaction of ethyl vanillin was complete, and the heating was stopped. After the reactor was cooled, the catalyst was filtered, and the catalyst was directly dried before use. The excess isopropanol was removed by rotary evaporation from the filtrate to obtain 1.33 kg of ethyl vanillyl isopropyl ether with a yield of 96% and a purity of >98%.

Example 13:

In reactor, add 1 kilogram of ethyl vanillin, 12 liters of n-butanols (the concentration of ethyl vanillin is 0.5mol/L), 0.2 kilogram of catalyst D and 0.25 kilogram of catalyst E, and charge into 1.2MPa hydrogen, be heated to React at 50°C for 20 hours, check that the reaction of ethyl vanillin is complete, stop heating, filter the catalyst after the reaction kettle is cooled, and dry the catalyst directly before use. The excess n-butanol was removed from the filtrate by rotary evaporation to obtain 1.34 kg of ethyl vanillyl butyl ether, with a yield of 97% and a purity of >98%.

Claims (5)

1. One-step method prepares the technique of vanillyl alcohol ether, it is characterized in that: raw material vanillin is dissolved in alcoholic solvent and is placed in reactor, adds nanometer ruthenium metal catalyst and immobilized tin phosphotungstic acid catalyst and is filled with 1～ 2MPa hydrogen, control the reaction temperature at 20-60°C, and the reaction time is 18-24h, and obtain vanillyl alcohol ether in one step through catalyst catalysis; wherein the nano-ruthenium metal catalyst is the product of oxide-loaded ruthenium trichloride and hydrogen reduction, Wherein the mass ratio of ruthenium trichloride to the oxide is 1: (20-40); the described solid-supported tin phosphotungstic acid catalyst is activated carbon-supported tin phosphotungstic acid, and the solid acid obtained by carbonizing furfural on the surface Catalyst; wherein the mass ratio of tin phosphotungstate to activated carbon is 1:(1.25-2), and the mass ratio of furfural to tin phosphotungstate is 1:(2-3). 2. The process according to claim 1, characterized in that the alcoholic solvent is methyl alcohol, ethanol, n-butanol or Virahol. 3. The process according to claim 1, characterized in that the oxide is aluminum oxide, titanium dioxide, silicon dioxide or ferric oxide. 4. technology according to claim 1, it is characterized in that the consumption of described nanometer ruthenium metal catalyst is 20～40% of raw material vanillin quality; 5-25%. 5. The process according to claim 1, characterized in that the concentration of the raw material vanillin in the solvent is 0.5 to 1.5 mol/L.